In order to realize large-sized images with high luminance displayed by a projection type display apparatus, a projection type display apparatus having a multi-lamp light source device including a plurality of light source lamps is proposed. For example, Patent Document 1 (Japanese Patent Application Kokai Publication No. 2001-359025, paragraphs 0013 to 0018 and FIG. 1) proposes a light source device for a projection type display apparatus, in which light fluxes from two light source lamps disposed facing each other are combined through the use of a prism disposed near light converging points of the light source lamps.
Patent Document 1 is Japanese Patent Application Kokai Publication No. 2001-359025.